It has been known that the deposition of cholesterol in the vascular system is an etiological cause of various diseases including coronary heart diseases. Among these, atheromatous arteriosclerosis is a form of arteriosclerosis which is characterized by the accumulation and hypertrophication of lipid, particularly cholesterol ester on the medium and large arterial wall.
Recently, it has been found that acyl-coenzyme A cholesterol acyl-transferase (ACAT) catalyzed the formation of cholesterol ester. Namely, the excessive accumulation of cholesterol ester on the arterial wall has connection with the increase of ACAT enzyme. Accordingly, it is expected that by inhibiting the ACAT enzyme, the esterification speed of cholesterol may be decreased, and the formation and development of atheromatous disorder caused by the excessive accumulation of cholesterol ester to the arterial wall may be controlled.
On the other hand, cholesterols in foodstuffs are absorbed as a free cholesterol, esterified by the action of ACAT enzyme, and then released into the blood in the form of chylomicron. Therefore, it is expected that by inhibiting ACAT enzyme the absorption of cholesterols in foodstuffs into the intestine may be controlled and the re-absorption of cholesterol released into the intestine may be also controlled.